Hybrid energy recovery system

ABSTRACT

A system for recovering energy from the natural and man made sources of wind, water and sunshine provides within a given local area wind, water and solar apparatuses for converting all three wind, water and solar energies to electrical power to provide a reasonably steady supply of electrical power at all times. The wind and water apparatuses may be double speed Savonius rotor electrical generating apparatuses each of which includes two Savonius type rotors mounted adjacent to one another for rotation about a common axis with the blades of the rotor units being arranged so that the rotor units rotate in opposite directions relative to one another under the influence of a given wind or flow of water. The electrical generator of each apparatus includes a field means attached to one of the two rotors and an armature attached to the other of the two rotors so that the field means and armature rotate relative to one another at a speed approximately double the speed of rotation of each of the rotor units about the common rotational axis.

CROSS REFERENCE TO RELATED APPLICATION

This application relates to Provisional U.S. Patent Application Ser. No.60/072,741 filed on Jan. 27, 1998, the filing date of which is claimedhere.

FIELD OF THE INVENTION

This invention concerns a hybrid system for recovering energy fromnaturally occurring energy sources such as the sun, the wind and flowingwater, and from presently wasted manmade sources of light, wind andflowing water, by converting the energy contained in these sources intoelectrical and mechanical energy to be used either locally close to theplaces of recovery or to be included into a far-reaching electricalpower transmission network, and it also deals more specifically with theconstruction of apparatuses and combinations of apparatuses used in themaking up of such hybrid energy recovery system.

BACKGROUND OF THE INVENTION

A hybrid energy recovery system is one wherein energy is recovered froma number of different energy sources located within a relatively smallarea such as, for example, the area surrounding and including the spaceoccupied by a given architecture such as a house, apartment, factory,office building or a set of such buildings. Such a hybrid energyrecovery system is known, for example, from: Russell Direct GainIndustrial Building Without Redundancy Has Quick Pay Back, proceedingsof the Fifth National Passive Solar Conference, University of Delaware.

There is increasing agreement around the world that people would benefitfrom a change from nuclear fuels, coal, oil and gas as energy sources toclean indefinitely renewable and locally available natural energysources such as sunshine, wind, and flowing water to generate usefulelectrical power. The use of each one of sunshine, wind and flowingwater as an energy source by itself has its strengths and weaknesses,such as time of day or night, season, weather conditions, location ofgenerators near to points of use, special land and directional andtopographic requirements, the amount and cost of required real estate,aesthetic considerations, safety considerations, noise considerations,etc. However, when these natural and manmade sources of energy are usedin combination to generate electrical power, they can go a long way insolving another major and heretofore expensive problem, namely that ofproviding a reasonably steady and continuous source of electricity forstorage in batteries and other energy storage devices and/or for use inpowering lamps, motors and other devices.

It is also important to local communities that the equipment required toconvert natural energy sources to electricity be easy to manufacture andassemble, be easy to install, and be easy to service and replace whennecessary by fully qualified local labor. This keeps the money to bespent in the community, and helps solve a current major worldwideproblem occurring in many communities and nations of having to spendvast amounts of monies out of town or out of the nation to payincreasing prices for increasingly scarce and unhealthy non-renewableenergy material such as nuclear fuel, oil, gas and coal.

Natural energy assets such as sun, wind, and flowing water can beconsidered as being of two types: (a) inherently natural, and (b)byproducts of human activities. For instance, we brightly lightbuildings to attract attention, parking lots to be safe, signs to beseen. This light is a byproduct of human activity and it is possible torecapture some of it with photovoltaic devices without interfering withthe purpose for which the light was initially intended. As anotherexample, it is possible for photovoltaic material to be carried on southfacing highway noise barriers to pick up enough light from theheadlights of passing trucks, buses and cars to supplement naturalsunlight picked up by the photovoltaics during daytime. In the case ofwind energy, thousands of trucks, buses, and cars driving down highwaysat high speed cause major gusts of wind which are often enhanced andchanneled by land formations and noise barriers. A series of properlydesigned wind powered electrical generators can generate electricityfrom these gusts. In the case of flowing water power, large amounts ofwater run from hills or buildings when it rains, and this flowing watercan be channeled and directed to small water wheel electrical generatorsat lower levels or into ponds that hold the water and release it whensupplemental electrical power is needed.

High buildings in heavily built up areas can be cost free mounts forsouth facing photovoltaics to capture solar energy from the sun or canbe used to channel wind or rain water to small wind powered or waterpowered electrical generators, and smaller flows of water can becombined and directed into larger flows to power turbines driving morepowerful electrical generators.

From what has been said above, one can visualize a number of highbuildings connected by glass enclosed walkways across streets, possiblyat several levels. Some walls that face roughly south may havephotovoltaic generating devices mounted on them. When wind is deflectedfrom buildings causing areas of high wind velocity, this high windvelocity can be used by putting a series of small rotor type windelectrical generators between the two walkways which will deflect andincrease the wind speed and electrical generation. Service could be madeeasy by access to the rotors through the ceiling of the lower walkway orthe floor of the upper walkway.

In considering a system for combining the recovery of solar, wind, andwater energy, it will be noted that solar energy recovery devices areleading the way with rapid technological breakthroughs. The efficiencyof the devices are increasing and the prices of them are falling.Reasonably efficient and reasonably inexpensive water-powered generatorsare also available. The conversion of wind power into electrical energyis, however, the crucial element in a natural energy recovery system.

Wind energy has the potential to be the major energy provider of arecovery system, but suffers from clinging to natural wind resourcesonly. The emphasis has been on natural wind and the few and costly sitesthat naturally have the necessary wind speeds. New developments havefocused on complicated windmills of the propeller and Darrieus rotortechnologies that supply high efficiency, but also have high initialexpense, require high towers in most locations, are subject to expensiveand dangerous servicing atop high towers, require a lot of space, cannoteffectively utilize intermittent gusts (which is very wasteful), and canbe destroyed by wind shears. These complicated windmills also requiretime to swing to face the quick changes in wind direction in the case ofpropeller-type units, and have uncertain stalling and starting problemsin the case of Darrieus designs. Both propeller devices and Darrieusdevices have niche applications where they do well, but these arelimited.

Transporting electricity long distances is increasingly expensive anddangerous, and the source of most service interruptions and accidents.The new rules separating distribution from generation furthercamouflages costs that are already misleading because emergency costsoften are paid by local police, fire departments, disasterorganizations, and the Federal government. With remaining largemonopolies, utility control boards are less effective, and individualshave little influence short of forming cooperative or generating theirown power on site. Even small wind generating and photovoltaics canoperate thermostats, pumps, and blowers to maintain critical heat andcommunications during protracted outages.

The Savonius rotor as a wind energy recovery device has long been usedfor such high torque applications as pumping water and grinding grain.It is a simple device which can, if well designed, use rotor unitsformed in one piece to very accurate standards and using new materials,with possibly self-lubricating properties that are recyclable andinexpensive. The rotor unit is then mounted on a vertical pipe or othersupport passing vertically through the center of the unit so that theunit revolves around the pipe when the wind blows onto the unit from anydirection with sufficient velocity. That is, the Savonius rotor can usewind from any and all directions at all times. This simple two-bladedSavonius rotor, or similar rotors with three or more blades, operates atrelatively low speeds in comparison to some other types of wind-poweredrotors and has usually been considered to be inefficient for electricgenerating purposes, with efficient generation of electricity usuallybeing considered to require higher rotor speeds than generally availablefrom Savonius rotors.

The object of the present invention is, therefore, to provide a hybridenergy recovery system for recovering energy in electrical and/ormechanical form from a combination of solar, wind, and flowing waterenergy sources, both naturally occurring and man made.

A further more detailed object of the invention is to provide aSavonius-type rotor apparatus which can be used for generatingelectrical power from wind power and which generates efficiently athigher speeds of electrical power production than do conventionalSavonius rotors, with such higher speeds of electrical power productionbeing obtained without gears or other mechanical speed-increasingdevices.

Another object of the invention is to provide a Savonius-type rotorapparatus of the above-mentioned kind which can also be used in theenergy recovery system of the invention to recover electrical energyfrom the energy of flowing water, and which can also be used forrecovery of solar energy, the Savonius rotor having a relatively largesurface area in comparison to propellers and many other types of winddriven devices and, therefore, being well suited to additionally serveas a solar energy recovery device.

SUMMARY OF THE INVENTION

The invention resides in a system for producing electrical energy fromcombined energy sources of sunshine, wind, and flowing water. Morespecifically, the invention resides in such a system wherein at leastthe apparatus for producing electrical power from wind is an apparatusmade up of two Savonius rotor units, with the two rotor units beingmounted end to end for rotation about a common central axis in oppositedirections of rotation and with the adjacent ends of the two rotor unitsrespectively carrying or being otherwise connected to field and armatureparts of an electrical generating device, which field and armature partscooperate during rotation of the rotor units to generate electricalpower, the speed of rotation of said field and armature parts relativeto one another being effectively double the speed of rotation of eachone of the rotor units relative to the common axis, so that theelectrical power is generated at a high speed or frequency more suitedto the efficient generation of electrical power than is the lower speedof either rotor unit taken by itself.

The invention also resides in the energy recovery system of theinvention including both a double speed Savonius rotor apparatus forgenerating electrical power from wind and another double speed Savoniusapparatus for generating electrical power from flowing water.

The invention further resides in making the rotor of the wind drivenelectric power generator of materials, such as ones including carbonfibers, whereby the material of the rotors themselves can be used aselectrical conductors, as electrical energy storage means, and/or asphotovoltaic devices for converting solar energy to electrical energy;and/or in providing separate photovoltaic elements on surfaces of therotors so that the rotors not only contribute to the recovery of energyfrom the wind or flowing water but also contribute to the recovery ofenergy from the sun. In the case where the carbon fibers are used forconducting electricity, they can be used as conductors for conductingthe electricity produced by the photovoltaic devices associated with therotors, as conductors for conducting electricity to or from parts of theelectrical generator associated with the rotors, or as conductors forconducting electricity in a control circuit associated with theelectrical generator.

The invention also resides in a double speed Savonius rotor apparatus ofthe above-mentioned kind wherein the apparatus includes a means forsensing the speed of each of the two rotors and an associated controlsystem for controlling the generator portion of the apparatus to controlthe speeds of the rotors through the use of a regenerative or dynamicbraking effect applied to the rotors by the generator, as for example,to keep the rotors from reaching possibly self-destructive speeds orfrom rotating at undesirable low speeds with the power absorbed by thegenerator in braking the speeds of the rotors being recovered asadditional useful electrical power.

The invention also resides in a construction of the double speedSavonius rotor apparatus particularly well adapted for use with flowingwater or in other situations where the apparatus is used in wet or dampenvironments.

The Wind Book by Jack Park published in 1981 by Cheshire Books in PaloAlto, Calif. has a photograph on page 75 of a three-tiered Savonius Srotor designed to generate electricity. In the background aretransmission lines and towers suggesting this was a serious effort todevelop wind electric generation by utilities. Traditional Savonius Srotors worked very differently from the wind electric Savonius rotors inthis patent application. The S rotors and the vertical shift towerrotated together all in one direction and the bottom end of the shaftturned the water pump in the well or other devices.

Park says in his write-up "A rotor that slows air down on one side whilespeeding it up on the other, as does the S rotor, is subject to themagnus effect: lift is produced that causes the machine to move in adirection perpendicular to the wind. Spin on a baseball causes it tocurve because of the magnus effect. An S rotor can easily experiencelift forces equal to three times the drag load placed on the supportingtower. Many owner-built S rotors have toppled to the ground becausetheir designers overlooked this phenomenon."

In addition to the vertical central shaft the picture shows a largeheavy iron external frame with a very large foot print plus 4 guy wiresand a large concrete base. Also, the rotors appear not to overlap thevertical shaft to deflect wind to the back side of the drag blade whichincreases performance substantially, according to Paul Gipe, author ofWind Power, for Home and Business published by Chelsea Green Publishing,White River Junction, Vt. in 1993. Gipe says on page 105 that 33% is thetheoretical amount of energy Savonius S rotors can extract from thewind. While on page 105, he states the betz limit for lift devices is59.3% but optimally designed rotors reach levels slightly above 40%.Usable energy is even less because energy is lost in transmissions,generators, and power conditioning (the equipment necessary to convertthe energy into a form we can use). There are also loses due to rapidchanges in wind speed and direction that are not accounted for in oursimple formulas. On page 62, he sums this up and comes up with anoverall efficiency of 29%. So there are hard numbers to back the casefor new state-of-the-art Savonius counter rotating wind electricgenerators on site which can supplement natural wind with man-madearchitectural contributions to wind speed as well as man-made windsotherwise wasted.

Moving water can be a particularly valuable contributor to hybrid energysystems because (1) it can be stored high up where it is collected andheld as potential energy to be released as needed, and (2) it cangenerate 24 hours a day regardless of weather and is usually mostavailable in winter when photovoltaics are least productive and whenenergy demand is highest. Once installed small and micro turbines cangenerate at up to ten times lower cost than photovoltaics.

Moving water rotors work best when they rotate at roughly the same speedas the speed of the water that is their primary source. Low head movingwater rotors turn slowly at speeds roughly similar to wind speeds. Sobasically the same counter rotors that generate electricity by doublegenerating speed should work well for low head water.

High head water moving fast but with smaller volume neet micro peltontype rotors which turn so fast they need fans to cool them and even soequipped wear out their rotors quickly. Here again counter rotatingrotors have the capacity to generate at the required High speed witheach counter rotating rotor that the water hits having to rotate at onlyabout half the speed of the generator.

Still other features of the invention will be apparent from the claimsand from the following description and accompanying drawings describingpreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an energy recovery system embodying thisinvention in association with an exemplary architecture.

FIG. 2 is a front elevational view of the system and architecture ofFIG. 1.

FIG. 3 is a fragmentary perspective, exploded view of a double-speedSavonius wind or water driven electrical power generating energyrecovery apparatus used in the system of FIG. 1.

FIG. 4 is a transverse sectional view taken on the line IV--IV of FIG. 3

FIG. 5 is a transverse sectional view taken on the line V--V of FIG. 3.

FIG. 6 is a complete perspective view of the double speed Savoniusenergy recovery apparatus of FIG. 3.

FIG. 7 is an elevational view of a modification of the double speedSavonius energy recovery device of FIG. 3.

FIG. 8 is an elevational view of another modification of the doublespeed Savonius energy recovery device of FIG. 3, with parts of thegenerator housing being broken away to reveal the enclosed field andarmature of the generator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The energy recovery system of this invention may be associated with manydifferent geophysical and architectural situations where sources ofsolar, wind, and flowing water energies are all available, although indiffering degrees depending on time of day, weather conditions, andother factors, within a small area, to provide a reasonably continuousand useful amount of electrical power to be used by lamps, motors, andother electrical appliances, with or without accompanying storagebatteries, in the local area or to be supplied to a more far-reachingelectric power transmission network, with the system also possiblyproviding mechanical power for directly mechanically powering mechanicaldevices such as pumps and grinders.

Referring to FIGS. 1 and 2, the system of the invention is shown appliedto an exemplary architecture. The illustrated architecture consists oftwo multi-storied buildings 10 and 12. As seen in FIG. 1, the twobuildings 10 and 12 are of generally square or rectangular footprintswith the building 10 having two vertical sidewalls 14 and 16 convergingto a corner area 18 and with the building 12 having two verticalsidewalls 20 and 22 converging to a corner area 24. Between the twobuildings are two elevated walkways 26 and 28 connecting the twobuildings 10 and 12, with the illustrated walkway 26 being located atthe second floor level of the two buildings and with the illustratedwalkway 28 being located at the fourth floor level of the two buildings.

For recovery of solar energy, both of the buildings carry one or morearrays 30 of photovoltaic cells or elements of known construction. Asillustrated, some of these photovoltaic arrays can be arrays 30 locatedon the roofs 35 of the two buildings, and other arrays can be arrays 32located at available places on one or more of the vertical walls of thebuilding, as for example between horizontal rows of windows 34 as shownin FIG. 2. The electrical power generated by the individual arrays areconducted by suitable conductors to a transmission cable 36 fortransmission to the inlet 38 of a local electrical energy receiving andutilizing means 41, the means 41, as mentioned, possibly includingvarious lamps and motors used locally in or immediately outside of thebuildings 10 and 12. The means 41 may also include storage batteries forstoring excess amounts of electrical energy during periods of peakelectrical energy production and for supplying amounts of make-upelectrical power during periods of low electrical power production.Further, the means 41 may also include or be a connection to afar-ranging electrical transmission network for supplying excess amountsof produced electrical power to the network.

For recovery of energy from water, the system of FIGS. 1 and 2 includesan arrangement of gutters and drains for collecting rainwater strikingthe buildings 10 and 12 and for channeling the collected water to one ormore water-driven electrical generating units. The arrangement ofgutters and drains and the number and construction of the water drivengenerators used in a particular application may vary widely. By way ofexample, in FIGS. 1 and 2 for each of the buildings 10 and 12 thegutters include gutters 33 for collecting rainwater flowing from theroof 35, and the drains include a drain 37 for conducting water from thegutters 33 to a water-powered electrical generator 40. The powergenerated by each generator 40 is conducted by a transmission line 42 tothe electrical power inlet 38 of the utilizing means 41.

As to the recovery of energy from wind, in the architecture of FIGS. 1and 2 between the two walkways 26 and 28, as seen in FIG. 2, are anumber of through-going passageways 44, each of which passagewayscontains a wind-driven electrical generating unit 46.

It will, therefore, be understood from FIG. 1 that when a wind isblowing generally in the direction of the arrow 48, the two walls 16 and22 of the two buildings 10 and 12 channel the wind toward thepassageways 44 and thereby significantly increase the speed of the windat the place where the wind encounters the generating units 46.Likewise, when the wind is blowing generally in the direction of thearrow 49, the two walls 14 and 20 of the two buildings 10 and 12 channelthe wind to the passageways 44 and likewise increase the speed of thewind as it encounters the generating units 46. The power generated byeach of the units 46 is transmitted to a transmission cable 50 whichconducts the power to the inlet 38 of the power-receiving means 41.

It should be noted from FIGS. 1 and 2 that having the walkways 26 and 28spaced vertically from one another by the equivalent of the height ofone floor of each building allows for such a design that thewind-powered generators can be made accessible for maintenance and/orreplacement from either the roof of the passageway 26 or the floor ofthe passageway 28.

Preferably, and as best seen in FIG. 1, the passageways 26 and 28 arelocated above a street 43, bordered by sidewalks 21 and walls 23,passing between the two buildings 10 and 12, the street being a two-waystreet as indicated by the broken arrows 25. Therefore, trucks and carsmoving along the street 43 and under the passageways create gusts ofwind which impact on the generating units 46 so that the generatingunits recover at least a part of the energy contained in those gusts andconvert it to electrical energy. Further, between each wall 23 and theadjacent building 10 or 12, on both sides of the passageways 26 and 28,as seen in FIG. 1, is a pond 47 of water which, depending on the time ofday, can be helpful in reflecting received sunshine onto thephotovoltaic arrays 32 carried by the buildings.

As mentioned, both the water-powered electrical generators 40 and thewind-powered electrical generators 46 of the system shown in FIGS. 1 and2 may take various different forms. Preferably, however, each of thegenerators 40 and 46 is of a type, referred to herein as a "double speedSavonius rotor electrical generator", which is described in more detailbelow in connection with FIGS. 3-7. For purposes of description, theapparatus of FIGS. 3-7 is referred to as a wind-powered one, but itshould be understood that it can also be used as a water-powered one.

Turning first to FIG. 3, a double speed Savonius rotor electricalgenerator embodying the invention is there shown generally at 52. Itincludes two rotor units 54 and 56 which are of substantially identicalconstruction and which can be manufactured economically in largequantities, possibly of plastic material with self-lubricatingproperties, or using ball bearings and other materials. Each rotor unitis of the well known Savonius design, with each rotor unit including twocircular end plates 58 and 60 and two blades 62 and 64. Each blade 62and 64 is of semi-cylindrical shape, and if wanted, the two blades ofeach rotor can be made by starting with a cylindrical tubular body andcutting the body along two lines extending parallel to the axis of thebody and located in a common plane passing through the axis of the body.The arrangement of the two blades of each rotor relative to one anotheris preferably such as shown in FIGS. 4 and 5, but other arrangements ofthe blades relative to one another, and even three or more blades, maybe used in each rotor without departing from the invention.

The two rotor units 54 and 56 are supported on a fixed pipe or shaft 66for rotation relative to the shaft about the shaft's longitudinal axis,as by suitable bearings 68 located at each end of each rotor unit.

Although the two rotor units 54 and 56 are of identical construction, animportant aspect of the invention is that they are mounted on thesupporting pipe 66 so as to rotate in opposite directions about the pipe66 when encountered by a wind traveling in any given direction. Inparticular, to obtain this difference in rotational direction, the tworotor units 54 and 56 are mounted on the pipe 66 so that their twosimilar end plates 60, 60 are located adjacent to one another as shownin FIG. 3. As a result of this, the blades 62 and 64 of the rotor unit54 face in directions opposite to the corresponding blades 62 and 64 ofthe rotor unit 56, as seen in FIGS. 4 and 5. Accordingly, whenencountered by a wind of any direction, the upper rotor unit 54 of FIG.3 will rotate in the direction of the arrow 70 and the lower unit 56will rotate in the opposite direction of the arrow 72.

As mentioned, Savonius rotors are known to operate at relatively lowrotational speeds which are considered not suited to efficientelectrical power generation. In the present invention, however, the factthat the two rotors 54 and 56 rotate in opposite directions is takenadvantage of to provide for the generation of electrical power at doublethe speed or frequency such power would be generated by using only asingle rotor unit. This is done by providing an electrical powergenerating device 71 between the two adjacent rotors 54 and 56 with thegenerating device being of the type having a field means 74 and anarmature 76. The field means provides a magnetic field or pattern ofmagnetic fields through which the armature moves, and the armaturecarries coils in which electrical power is generated as a result oftheir movement through the magnetic field or fields of the field means.

Various different types of electromechanical electrical power generatingdevice may be used as the power generating device 71. The device may beone generating either AC power or DC power, depending on the use towhich the power is to be put. For example, L. Kamm, UnderstandingElectro-Mechanical Engineering, The Institute of Electrical andElectronic Engineers (1996), at pages 67 to 81 describes a number ofgenerators, and a number of motors which could be reversely driven asgenerators, that could be used as the generating device 71, theseincluding both devices with permanent magnet fields and devices withwound fields.

Normally, in an electrical generator, one or the other of the fieldmeans and armature is fixed relative to the ground and the other of thefield means and armature is carried by a shaft or other member supportedfor rotation relative to the ground, so that the speed of electricalgeneration is directly related to the speed at which the rotated one ofthe field means or armature is rotated relative to the ground. In thepresent instance, however, the field means 74 of the generator 71 ismounted to and carried by the outwardly facing side of the end plate 60of one of the rotor units 54, 56 and the armature 76 is mounted to andcarried by the outer face of the adjacent end plate 60 of the other oneof the two rotor units 54 and 56. In FIG. 3, the two rotor units 54 and56 are shown axially exploded from one another along the length of thepipe 66 to better reveal the field means 74 and 76. In the operationallyassembled condition of the two rotor units 54 and 56, however, the tworotor units 54 and 56 are located closer to one another so that thefield means 74 and 76 of the electrical power generator move directlyadjacent to one another to produce electrical power in the armature 76.The power which is produced in the armature 76 is conducted to atransmission line 78 passing through the pipe 66 by a suitable means(not shown) such as slip rings and brushes or mutual induction coilsbetween the armature 76 and pipe 66.

Due to the illustrated construction of FIG. 3 it will, therefore, beunderstood that when a wind rotates the two rotor units 54 and 56 inopposite directions, the power generated in the armature 76 of thegenerating device will be generated at a speed or frequencyapproximately double that of the speed at which electrical power wouldbe generated by a single one of the rotors 54 or 56 operating by itselfto drive an associated generator. It should also be mentioned that invery strong winds or gusts of winds, it is possible that the speeds ofthe rotor units 54 and 56 may tend to reach self-destructing values atwhich vibrations and other forces become too great for the rotors and/ortheir supports to withstand, and during winds of low velocity the rotorunits may rotate at very low speeds at which only low amounts of powerare generated. Therefore, it may be desirable to associate a controlwith the apparatus to inhibit rotation of the rotor units at eitherexcessively high speeds or excessively low speeds. Further, if thegenerator unit is one producing AC power, it may be desirable to havethe power generated at a substantially constant frequency, such as forexample, the U.S. standard frequency of 60 Hz. In this latter case, itis therefore desirable to associate a control system with the apparatuswhich maintains the sum of the speeds of the two rotor units at asubstantially constant value so as to have the electrical powergenerated at a constant frequency. If this frequency at which theelectric power is constantly generated is either too high or too low, itcan be converted to the desired output frequency using a conventionalfrequency converting circuit.

To effect a control of the speed of the rotor units as suggested in thepreceding paragraph, a control unit 80, as shown in FIG. 3, can beprovided which senses the sum of the rotational speeds of the two rotorunits 54 and 56. This detection can be done by means of separaterotational speed detectors associated with each of the two rotor units54 and 56 and by means of a circuit within the control unit 80 whichsums the values of the two speed detections. However, preferably and asshown in FIG. 3, the control unit 80 detects the sum of the rotationalspeed of the two rotor units 54 and 56 by detecting the frequency atwhich electrical power is generated in the armature 76, as suchfrequency is directly related to the sum of the speed of the two rotorunits. A signal related to this detected frequency appears on the line81. Then, in response to this sensed indication of the sum of the speedsof the two rotor units, the control unit 80 controls, over the line 83,the strength of the magnetic field or fields produced by the field means74, it being taken in this case that the field means 74 is one producinga field of controllably variable strength, such as one having fieldcoils the current supplied to which is controlled by the control unit80. As the field strength is increased, the torque imposed on the tworotor units 54 and 56 by the generator increases to slow down the speedof rotation, and similarly when the field strength is reduced, thetorque applied to the rotor units is decreased to increase the speed ofthe rotor units. Further, when the field strength is increased to reduceexcessive speeds of the rotor unit, the effect produced is aregenerative braking one on the two rotor units 54 and 56 which causesadditional power to be generated by the generator. Thereby, the excessenergy in gusts of wind which would otherwise tend to rotate the rotorunits at excessive speeds is recaptured as additional electrical energy.

It should also be noticed that the field means 74 on the rotor 56 andthe armature 76 on the rotor 55 are of significant mass and therebyprovide for each rotor unit a flywheel effect tending to resist changesin the speed of each rotor unit, and this flywheel effect therefore alsotends to inhibit rotation of the rotor units at excessive speeds byshort gusts of wind. If additional flywheel effect is desired, it can ofcourse be achieved by adding additional weights to the two rotor units.

FIG. 6 shows the apparatus 52 of FIG. 3 in completely assembled form inwhich it will be noted that the space between the two rotor units 54 and56 containing the electrical generator 71 is enclosed by a cylindricalhousing 82 fixed to the pipe 66. In this case, the lower end of the pipeis supported on the ground, or other support structure by a holder 84,and three or more guide wires 86 connected between the housing 82 andground may be used to vertically steady the apparatus in the event nosupport is available for holding the upper end of the pipe 66.

Also, it should be understood that, although in FIGS. 3 and 6 theapparatus 52 is shown as being comprised of only two rotor units 54 and56, if wanted, additional such rotor units may be placed on the pipe 66adjacent to one another with an electric generating means, similar forexample to the generator 71 of FIG. 3 being provided between eachadjacent pair of rotor units.

Also, each of the rotors 56 and 56 of the apparatus 52 may be madelonger than shown. In general, as each rotor unit is made longer, thepower recovered by that unit is increased. A convenient way of making arotor unit longer is to merely attach to it, end to end, another rotoridentical to it.

It should also be understood that in a hybrid system such as that ofFIGS. 1 and 2, the apparatuses used for recovery energy from the wind orfrom flowing water need not necessarily be used exclusively for thegeneration of electricity. Instead, one or more of the provided winddriven units or flowing water driven units may be used partially orentirely for directly driving associated mechanical devices such aspumps and grinders.

Also, the rotor units 54 and 56 of the apparatus 52 are of relativelysimple construction and can conveniently be made from materialsproviding other structural and functional benefits. For example, thematerial used in making the rotor units 54 and 56 may be a carbon fibercontaining one such as described in the article by Lori Valigra entitledCarbon-fiber Material May Open the Door to Smart Structures, ChristianScience Monitor (Mar. 26, 1998). Using such material, the rotors can bemade to use the carbon fibers for conducting electricity, for storingelectrical power and/or for photovoltaically converting the energy ofthe sun into electrical power, with the fibers used as electricalconductors being used to conduct electrical power from the photovoltaicdevices, being used to form part of the electrical generating circuit,or being used as a part of a control circuit for the generator.Additionally, or instead of using the carbon fibers as a photovoltaicmeans, separate photovoltaic devices may be mounted to various surfacesof the rotor, as indicated in FIG. 6 wherein such photovoltaic devicesare indicated by broken lines at 63.

The use of structural materials, such as the one mentioned in thepreceding paragraph, having energy storage capacities is further notlimited to the rotors of the generating apparatus 52, but instead mayalso be used in making other parts of the hybrid system. For example,various walls of the buildings 10 and 12 could be made of such materialso that the walls serve not only as structural parts of the buildingsbut also as units for storing energy recovered by one or more of theenergy recovery devices of the system.

Another material that may be used in making the above describedgenerating apparatus 52, especially for parts of the electricalgenerating unit or for a control unit, as hereinafter described in moredetail, is the silicon carbide material described by Lee Dye in an Oct.12, 1998 article distributed by the Los Angeles Times Syndicate andentitled Advanced Chip Revs Up Electric Car Technology, so as to allowthe involved parts to be made of small size, to operate well over a widerange of temperatures, and to have extremely long and reliable servicelives.

FIG. 7 illustrates a modification 52a of the apparatus 52 of FIG. 6. Theapparatus of 52a is similar to that of the apparatus 52 except that eachof the two rotor units 54a and 56a at each of its axial ends has afrustoconical collar 88. These frustoconical collars 88 serve twopurposes. First, the two collars 88 which are adjacent to one anotherform a housing 90, replacing the cylindrical housing 82 of FIG. 6, forhousing the associated electrical generator 71. Secondly, the twocollars 88 of each unit 52a and 56a act to channel wind to the blades62, 64 of the rotor unit in such a way that the speed of the wind whichengages the blades is greater than it would otherwise be, and so thatthe two rotor units are each rotated at a rotational speed somewhathigher than would be the case without the collars 88, 88.

The above described double speed Savonius rotor electrical generatingunits 52 and 52a may be used so as to be driven either by wind orflowing water. In the case of being powered by wind the axis or rotorrotation is usually vertical, as shown in FIGS. 3, 6 and 7, but ifwanted horizontal or tilted orientation of the rotational axis may alsobe used. In the case of being powered by flowing water, the rotationalaxis is usually positioned horizontally with the water being dischargedonto the rotor units from above the rotor units. Preferably, in thesystem of FIGS. 1 and 2, the wind powered generators 46 are double speedSavonius rotor electrical generating units such as the herein describedunits 52 or 52a, but with the generator 46 having their rotational axespositioned horizontally. In the latter case, as shown in FIG. 2, thedrain 37 supplying each generator 40 at its lower end is divided intotwo parts 39a and 39b to approximately divide the flow of water into twoparts each supplied to a respective one of the two rotor units 54 and 56(or 54a and 56a) of the generator.

In the above description, the wind powered double speed Savonius rotorelectrical generating units 52 and 52a have been shown as ones whereinthe rotor units rotate about a vertical axis defined by a centralvertical pipe. If desired, however, such device can also be operated tobe driven by the wind or flowing water, with the axis of rotor rotationpositioned horizontally. FIG. 8, by way of example, shows a modificationof the device of FIG. 3 which can be powered by either wind or flowingwater and which additionally is made so that the electrical generatingunit is enclosed and sealed against moisture, thereby making theapparatus well suited for use in wet and damp situations.

Referring to FIG. 8, the involved double speed Savonius apparatus isindicated generally at 90 and has two counter rotating Savonius rotorunits 92 and 94. The rotor 92 is fixed to a shaft or horizontal axle 96and the rotor 94 is fixed to a horizontal axle 98 aligned with the axle96. A generator unit 100 is located between the two rotors 92 and 94 andincludes an enclosed housing 102 fixed relative to the ground by asuitable support stand 104. The axle 96 is supported at its left-handend by a moisture sealed bearing unit 106 carried by a stand 108, and atits right end extends into the housing 100 and is supported for rotationrelative to the housing 100 by a moisture sealed bearing unit 110.Likewise, the shaft 98 is supported at its right end by a moistureshield bearing unit 112 carried by a stand 114, and at its left-handend, extends into the housing 102 and is supported for rotation relativeto the housing by a moisture sealed bearing unit 116.

Within the housing 102, is a field means, indicated generally at 118fixed to and carried by the shaft 96, and a cooperating armature,indicated generally at 120, carried by and fixed to the shaft 98. Theshaft 94 rotates in the direction of the arrow 122, and the shaft 96rotates in the contrary direction indicated by the arrow 124. Therefore,the field 118 and armature 120 of the electrical generator, as in thecase of the previously described apparatuses 52 and 52a, rotate relativeto one another at a speed approximately double the speed of each of thetwo rotors 92 and 94, or more precisely at a speed equal to the sum ofthe absolute speeds of the two rotors 92 and 94.

It should also be noted that in placement of wind powered apparatuses,such as those described above at 52, 52a and 90, rigid stands can beused to mount the apparatuses on the roofs of flat top buildings or ontothe south facing roofs of buildings with pitched roofs. In the making ofsuch frames, it is desirable to have them constructed so as todistribute stress over a large area of the associated roof. Photovoltaicarrays or panels can then be mounted onto the south facing sides of theframes in a manner allowing vertical positioning of the panels or arraysto keep them from becoming covered with snow and ice in the wintertime.These panels would pick up reflected sunlight from ponds and snow on theground very effectively. The heat produced on the underside of thephotovoltaic devices will cut into efficient electrical generationunless the heat is drawn off to keep the temperature below 70° or 80° F.This heat could be used to melt snow and ice on the photovoltaic devicesand to heat the pipe stands and the rotors through which the pipe standspass. Horizontal counter rotators could be mounted at the top of thepipe stand just north of the photovoltaic devices where they would beheated by the photovoltaics in the winter to melt snow and ice. Inspring and fall the bottom of the panels would be slid southwardly andthe tops downwardly to a place on the face of the panels at the mostefficient angle for the spring season and for the local latitude. At thestart of summer, the panels would be slid further south and down to themost effective angles for maximum collection for the latitude. In thefall the angle would be set back to the spring setting and secured. Inall positions, the panels would deflect generally southerly directedwinds into the rotors. The back or north side of the frame would besloped similar to the south side and, if covered, would similarlydeflect generally northerly directed winds into the rotors.

The closed in north slope could form a watertight and insulatedenclosure with a disappearing staircase from the hall below. Two sturdyinsulated doors with window lights at each end would give good access tothe roof at both ends. The door bottoms should be high enough above theroof level to have a watertight solid section below them to keep anyrain or melting snow out. Tools and supplies could be stored under theeaves. A trap door opening upward could cover the staircase opening andplug the staircase opening to provide a continuous level floor to workon. Ideally, the covered stand should be long enough in the east to westdirection to easily accommodate a pipe stand with rotors and generatingmodule attached even though one may start with only a few panels androtors. This way one can economically start up a system with only a fewpanels and rotors to keep the associated building livable and safeduring dangerous outages, and later more panels and rotors can be addedas may be desired. If particularly dangerous storms are anticipated,pipe stands and rotors could be carried inside until the storm haspassed.

What is claimed is:
 1. A system for recovery of energy from acombination of natural and man made energy sources, said systemcomprising:a wind apparatus including a wind driven rotor and anassociated electrical generator for generating electrical power fromwinds, a water apparatus including a water driven rotor and anassociated electrical generator for generating electrical power fromflowing water, a solar apparatus including an array of photovoltaicdevices for generating electrical power from the sun, said windapparatus, said water apparatus and said solar apparatus being locatedin close proximity to one another and each having an output on which theelectrical power generated by the apparatus appears, an electrical powerreceiving means having an input in close proximity to said apparatuses,and means for transmitting the electrical power appearing at saidoutputs to said input; wherein: said wind apparatus, said waterapparatus, and said solar apparatus are all associated with a givenarchitecture, and said architecture includes two walls which convergetoward one another and toward an opening through which wind may pass, sothat wind moving generally in the direction toward said two convergingwalls is channeled to said opening so as to have a greater speed whenpassing through said opening than it would in the absence of said wallsand openings, and said wind apparatus is located in said opening, andsaid architecture includes means for collecting rainwater striking saidarchitecture and for channeling the collected rainwater to said waterapparatus, and said water apparatus is a double speed Savonius rotorelectrical generating apparatus.
 2. A system for recovering energy froma combination of natural and man made energy sources as defined in claim1, wherein:said two walls are respectively walls of two buildings spacedfrom one another and connected to one another by an elevated walkwaywhich connects said two buildings and which contains said opening.
 3. Asystem for recovering energy from a combination of natural and man madeenergy sources as defined in claim 2, wherein:said elevated walkway islocated above a street so that gusts of wind generated by vehiclestravelling toward an undersaid walkway impact on said wind apparatus tocause said wind apparatus to generate electrical power from said gusts.4. A system for recovering energy from a combination of natural and manmade energy sources as defined in claim 1, wherein:said wind apparatusis a double speed Savonius rotor electrical generating apparatus.
 5. Asystem for recovering energy from a combination of natural and man madeenergy sources as defined in claim 4, wherein:said double speed Savoniusrotor electrical generating apparatus includes two rotor units mountedadjacent to one another for rotation about a common axis of rotation,each of said rotor units has at least two blades and with the blades ofthe two units being arranged that the two rotor units rotate in oppositedirections about said common axis under the influence of a given wind,and an electrical generator located between said two rotor units, saidelectrical generator having a field means and an armature with saidfield means being carried by one of said rotor units and with saidarmature being carried by the other of said rotor units.
 6. A system forrecovering energy from a combination of natural and man made energysources as defined in claim 5, wherein:each of said rotor units hasfirst and second axial ends and a frustoconical collar positioned ateach of said axial ends to channel wind to the blades of the rotor unit.7. A system for recovering energy from a combination of natural and manmade energy sources as defined in claim 1, wherein:said double speedSavonius rotor electrical generating apparatus has two rotor unitsmounted adjacent one another for rotation in opposite directionsrelative to one another about a common horizontal axis, and said meansfor conducting collected rainwater to said water apparatus includes ameans for dividing the flow of collected rainwater into approximatelytwo equal parts and for supplying said two equal parts respectively tosaid two rotor units of said water apparatus.
 8. A system for recoveringenergy from a combination of natural and man made energy sources asdefined in claim 5 wherein:a control unit is associated with said doublespeed Savonius rotor electrical generating apparatus, which control unitsenses the speeds of said rotor units and in response to said sensedrotor unit speeds controls the speeds of said rotor units by controllingsaid electrical generator to controllably vary the strength of themagnetic field created by said field means and thereby the torqueexerted on said rotor units by said generator.
 9. A system forrecovering energy from a combination of natural and man made energysources as defined in claim 8, wherein:electrical generator is one whichgenerates AC electrical power, and said control unit senses the speedsof said rotor units by sensing the frequency of the AC power generatedby said electrical generator.
 10. A system for recovering energy from acombination of natural and man made energy sources as defined in claim9, wherein:said electrical generator is one having a field means ofcontrollably variable field strength, and said control unit controls thespeed of said rotor units by controlling the field strength of saidfield means to exert a regenerative braking effect on said rotor units.11. A system for recovering energy from a combination of natural and manmade energy sources as defined in claim 5, wherein:at least one of saidrotor units of said double speed Savonius rotor carries photovoltaicmeans for converting received solar energy into electrical energy.